In recent years, in the field of touch panels, projected capacitive touch panels have been widely used for PDA, mobile phones, and the like, and an attempt to increase the size of a touch panel of this type has started. In increasing the size of a panel, a low resistance of a transparent electrode is essential, and as technologies for achieving this low resistance, a method for forming a sensing section of capacitance using reticulated conductive thin wires is described in, for example, Patent Documents 1 and 2. The forming method of reticulated conductive thin wires described in these documents is concerned with a printing system of a conductive ink or thinning by means of photolithography of ITO or a metal thin film. However, these methods involve such problems that in the former printing system, it is difficult to stably form thin wires with a wire width of not more than 20 μm, whereas the latter involves such a problem that the costs are high because the photolithography step is constituted of plural steps.
On the other hand, a method in which low-resistance conductive thin wires are formed from a silver image obtained by development of a silver halide photographic photosensitive material is investigated in the field of an electromagnetic wave shielding film or a printed wiring. This development system is stable in terms of manufacturing steps because various patterns can be formed by means of exposure through a mask and a subsequent development treatment. As for the development system, for example, Patent Document 3 can be exemplified, and working examples in which reticulated patterns having a thin wire width of 20 μm and a lattice spacing of 250 μm have a surface resistivity of from 50 to 100Ω/ are described therein.